35" tires cause a lot of drag; noticeable decrease in power?

[TyCorr]

Ya'll get worked up too easy. Don't hate, educate

You have a good point. We've had umpteen threads where this.gets corrected. I mean if you go into a tire shop and ask "how tall is a 305?" The guy will give you "that look". We all know what look Im referring to.

 

[powerlifter405]

I went from stock 265/75/16 tires to 315-75-16 Not even noticeable once I turn the chip on. She'll peel off the Duratracs all day if I let her!

Same here.
I used a 6" lift, 315 pro-comp XT's. I lost a little top end but day to day I noticed no difference in daily driving power. My mileage stayed the same. I was lucky that I got nearly 18 all the time. I did get a best of 21 w/ factory tires on a trip but I think I had a tail wind and did 65 on a slower limited highway vs normal.

@ 70-75 I could get 18 any faster and it dropped to about 16-17 at 80.
I could spend 2-3 hours 4wheelin in the desert and still calculate by hand 16 mpg.

I regret getting rid of my 7.3. I can get 18 in the 6.4 but it is super picky and I need to be 1800rpms and below. Two different animals but I am going back to the 7.3 by the end of the summer. It will better suit my needs.

If you have a good tune I wouldn't sweat the decision to go 35's.

 

[always-strokin]

315 has absolutely nothing to do with 35" nominal tire size. God I hate it.when people.say that. My 34" waist size is a 13d shoe size. See how dumb that sounds?

315 is 315mm. The width of that particular tire. Divide by 25 and it'll tell you the width of your tire.

My truck has 265k miles on it and has been lifted the entire time. I went to 35s last summer and before that i never went smaller than a 37. Tuned and towing for the first 245k. As in never unhooked from the trailer. Trans was fine. Maintenance is key.

I couldnt imagine running a 7.3 with 4r100 and 3.73 gearing with smaller than a 33" tire. Stock size the ***kin thing is screaming to tow at 70mph. Add some power and 35s are the ideal.size for an otherwise stock truck. I in fact prefer how the 35s stretch out the duration of shifts and keep the.charger loaded. With some moderately larger injectors(175/80) the truck was perfect.

35&37 are perfect tires for a superduty. I can see how some guys would prefer a level or mild lift and 33s too.

Awesome reply, thanks for the input.

In my 7.3 I had no problems. I had 4.10s tho. Truck loved 35s. My 6.0 on the other not so much. My trans always wants to shift lost some low end. Mileage went down.... Now the tires I had before measured 34.5" "275/60r20" and the truck loved them could smoke them all day long. While yes turning the larger tire is gonna take more power the weight of the tire and wheel combo can make a huge difference. According to my dealer who could be blowing smoke.... My wheels "20x10 hostages" weigh in at around 40lbs the toyo mt in 35x12.50r20 weighs in around 80lbs... Now that's a 120lbs a wheel and tire.... My stock setup weighed... Close to 90lbs I believe maybe less.... That's a lot of weight to turn ....


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I've got 4.10's on my 7.3 and 35's also. But 120lbs a tire Thats insaneeee dude!

 

[smokedout250]

I just rotated them yesterday and it's the heaviest combo I've had on a truck my next tire will be a lighter a/t




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[7.3 Whitey]

I've got 4.10's on my 7.3 and 35's also. But 120lbs a tire Thats insaneeee dude!

Did you ever have them with 3.73s? Just curious how the stock truck would feel with 4.10s.

 

[CSIPSD]

I far prefered driving with 37's and 3.73's over the 4.30's I have now... the ONLY time the 4.30's shine is around town driving, otherwise the 3.73's kick there ass.

 

[always-strokin]

I just rotated them yesterday and it's the heaviest combo I've had on a truck my next tire will be a lighter a/t




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Holychit man... thats gotta be robbing hp and mpg w/ 120lb/side combo!

Did you ever have them with 3.73s? Just curious how the stock truck would feel with 4.10s.

Sorry bud I have not. The 410s are stock and I have never had the need to swap gears. Now, I WILL say that towing w/ 35's and 4.10s on STOCK tuning sucks major ass.. it took a LOT of pedal to get the load moving, especially when on a hill. W/ tuning, I'll spin the tires w/ an 8k load going uphill leaving a gravel driveway.

 

[7.3 Whitey]

OK. Thanks for the info.

 

[always-strokin]

Anytime man

 

[Zaairman]

Empty, didn't notice a huge power loss, very slight. Mileage will decrease 1-2 MPG. I consistently average 16.5 now.

Only time I don't like my 35s, is when towing in the 8-10k range on the highway when you hit hills. You've either gotta tow at 75-80 to keep the boost up, or slow down to about 60 and let it shift into 3rd.

 

[TyCorr]

Empty, didn't notice a huge power loss, very slight. Mileage will decrease 1-2 MPG. I consistently average 16.5 now.

Only time I don't like my 35s, is when towing in the 8-10k range on the highway when you hit hills. You've either gotta tow at 75-80 to keep the boost up, or slow down to about 60 and let it shift into 3rd.

Tuning....

 

[always-strokin]

^truth. Tuning helped a TON w/ my 35s

 

[TyCorr]

I meant that is tuning related. Not really anything to do with the tires other than they are making the tuning show.its weaker points.

 

[7.3 Whitey]

Yup. Just got my truck tuned.
It is simple physics. From a stock (99-03) 31 inch to a 35 inch tire, you spread out the gear ratio to a 3.30 gear ratio …
But … I just tuned my truck. Transmission profiles with more power do help A LOT
You also have to remember a 7.3 auto came with no catalyst (99-03) and the manual did have a catalyst. Probably the reason for the shoddy tuning was to reduce emissions.
This thing tuned is a whole other truck.
I would see what your goals for the truck are too. Wind resistance sucks, even leveled with 35s, compared to stock. Especially with loads in the bed and towing.
So racing etc. Just put a leveling kit on. I can off road pretty well too.
Putting a lift for more clearance for movement in the tires and not pulling off a fender help to.
If its for looks/coolness do you. Just remember it can become $$$ if you change your mind.

 

[TyCorr]

This is what will kill you about tires. If you don't change your gear ratio, regardless of power, physics WILL win. You have to rev higher in a given gear to get to the next. It is that simple.

Thats the idea regardless of tire.size. Running through the engines powerband and then going to the next whenever there is a cue. Your right foot controls when a shift occurs.

And I dont know what you fudgepackers are smokin' but 35s are basically the perfect tire on trucks with 3.73 gears. Decent tuning will leave lowend acceleration intact but stretch the gears out and reduce the rpms while cruising on highways at 70+. Stock.tires and a highway equals a lawntractor getting the piss wound out of it. No bueno.

 

[TyCorr]

Yup. Just got my truck tuned.
It is simple physics. From a stock (99-03) 31 inch to a 35 inch tire, you spread out the gear ratio to a 3.30 gear ratio …
But … I just tuned my truck. Transmission profiles with more power do help A LOT
You also have to remember a 7.3 auto came with no catalyst (99-03) and the manual did have a catalyst. Probably the reason for the shoddy tuning was to reduce emissions.
This thing tuned is a whole other truck.
I would see what your goals for the truck are too. Wind resistance sucks, even leveled with 35s, compared to stock. Especially with loads in the bed and towing.
So racing etc. Just put a leveling kit on. I can off road pretty well too.
Putting a lift for more clearance for movement in the tires and not pulling off a fender help to.
If its for looks/coolness do you. Just remember it can become $$$ if you change your mind.

Are you drunk? I feel like im at the local bar and some guy is axsplaining fizzsicks to me...

You keep referencing physics but what are your qualifications?

 

[MoneyWellWasted]

got 35s n 3.73 gears in my truck its the perfect combo. i dont lose any low end even with the trailer hooked up and rpms are low when on the highway. goin to 35s helped my mileage

 

[TyCorr]

got 35s n 3.73 gears in my truck its the perfect combo. i dont lose any low end even with the trailer hooked up and rpms are low when on the highway. goin to 35s helped my mileage

Exactly...

 

[CSIPSD]

Agreed... LOL

 

[7.3 Whitey]

Stop and go you lose it. In town I lost mileage, but this tune is helping keep it closer to 1750 rpms without me driving slower than an old man with a walker.
Stock I was closer to 2k RPMs most of the time.